广西木薯燃料乙醇项目能效评估

广西具有丰富的木薯资源,以木薯为原料生产的燃料乙醇是一种可再生的燃料。采用净能量和净可再生能量两个指标评估木薯燃料乙醇系统的能量和可再生能量生产的效率,并对木薯乙醇在生命周期内与外界环境的能量交换进行了统计,把能量消耗按照燃料和其副产品进行了分配;以及按照是否再生进行了分别统计。计算结果表明,使用木薯生产燃料乙醇在能量生产和再生能量生产上是可行的,木薯乙醇的净能量为2．417MJ／L,净可再生能量是2．458MJ／L;广西的木薯资源每年能净产出相当于3．508万t汽油的可再生燃料。木薯单产和化肥用量是提高能源利用和再生能源的关键因素;加强副产品的开发有利于提高系统的能效,使用可再生的有机肥代替化肥,能有效的提高系统的可再生性。

Evaluation on energy and renewable energy production efficiency of cassava in Guangxi

Guangxi has plentiful cassava resource,which is an ideal feedstock for production of renewable fuel ethanol.In this paper,net energy value (NEV) and net renewable energy value (NREV) are presented to assess energy and renewable energy production efficiencies of cassava ethanol system respectively.Energy exchanges of such system are estimated during its life cycle;meanwhile,energy consumptions are allocated between fuel and its byproducts,and it is also divided into renewable part and nonrenewable part. The results show that cassava-ethanol system was feasible in energy and renewable energy utilization.The NEV and NREV of cassava-ethanol system are 2.417 MJ/L and 2.458 MJ/L respectively.It can annually produce renewable fuel ethanol as much as 35.08 thousand tons conventional gasoline,when cassava resource in Guangxi region is fully developed.Yields and fertilizer uses are key factors to improve NEV and NREV in agricultural process.Byproducts utilization helps to increase NEV,and replacement of chemical fertilizer with organic fertilizer improves system renewable.